If you switch to that 3rd class, you will find where the quests start - only 1 visible on the map.
Coast of Opportunity is designed to let you level from 1 to 42 very quickly. Add in Xaviera and you can get to 50ish very quickly.
Monsters are tougher but quest rewards are better and let you properly equip yourself for the zone. The learning curve in Coast of Opportunity is much steeper than in the other zones, but the quest XP reward is much higher to compensate. You may find you want to stick with your current 2 classes for a while and come back to CoO later?
As a guide:
Heffner Camp is for about 1-20;
Fellowship of the Singing Spring - 20-25;
Lyonsyde Tribe is about 25-30;
Desert Investigation Post - 30-35;
Quodate Plains - 36-42.
Quests on Quodate Plains become quite a bit tougher and I find whichever class I try to play, there are a couple I tend to leave alone until I'm about half-way around Xaviera and then come back to complete.
Also, the House Maid is located in Heffner Camp - World Search for "Nicole Rebecca" - and she has some highly amusing identity issues leading to her referring to herself in the 3rd person.